Question

What is the sum of a 23–term arithmetic sequence where the first term is 9 and the last term is 163?

Answer 1

use the formula:\[\frac{n(first+last)}{2}\]

Answer 2

so (9+163)

Answer 3

/2

Answer 4

good, times 23, since thats the number of terms

Answer 5

way back when, before they had notations for this, they used words; and they had 2 different thrms for it that amounted to if the number of terms was even or odd

even number:\[\frac{n}{2}(first+last)\]
if it was odd\[n\frac{first+last}{2}\]